Airfoil or hydrofoil lift augmentation by use of various arrangements of slot emerging jets are already well known in the art as disclosed for example in U.S. Pat. Nos. 2,885,160, 4,457,480 and 4,682,746. The condition of the emerging jets is characterized by the jet flow momentum coefficient, which is essentially the ratio of jet momentum to the flow momentum of the foil travel speed. Such emerging jet arrangements involve: (1) a Coanda-effect tangential wall jet suitable for lift augmentation in one operational mode under higher travel speed conditions where the jet momentum coefficient is of low to moderate value; or (2) a jet ejected from the foil trailing edge at an angle to produce a jet-flap operational mode especially suitable for lift augmentation at low speed where the available jet momentum coefficient is high; or (3) a directable nozzle for vectoring of jet reaction control forces at zero speed conditions. Each one of the foregoing three operational modes is limited in suitability for force augmentation to a single range of either available momentum coefficient or speed as referred to. It is therefore an important object of the present invention to provide for extended lift augmentation under all conditions of speed and/or available jet momentum coefficient by means of a single trailing edge wall jet configuration under selective switching between different operational modes to thereby extend lift augmentation under all speed conditions between zero and high speed for the airfoil or hydrofoil.